1. Field of the Invention
The present invention relates to an output apparatus for use in a word processor such as a typewriter or the like or in a computer or the like and, more particularly, to a pattern output apparatus for outputting patterns based on a dot representing system.
2. Description of the Prior Art
Various kinds of output apparatuses have been developed as output apparatuses of various equipment. Recently, a pattern output apparatus based on the dot representing system has come into wide use. This is because it can extremely easily form a number of kinds of pattern outputs. For example as such an apparatus, a CRT display of the dot refresh type, wire dot printer, thermal printer, etc. can be mentioned. In the CRT display of the dot refresh type, in general, a pattern of a character or symbol (hereinbelow, referred to as a font) is accessed by a code and the font read out is temporarily stored in a video RAM, then this font is repeatedly read out at a high speed and is displayed on the CRT.
FIG. 2 is a diagram showing the correspondence between the ASCII codes which are generally frequently used and the patterns of characters or patterns. To apply this relation to the pattern output apparatus of the dot representing system, all fonts each having a size of 8.times.16 bits, for instance, are preliminarily stored in a memory such as a ROM or the like. When one desires to display font "A" among those fonts, the actual readout address in the ROM is obtained by way of (reference address in the ROM)+(16 .times.41H) since the code of font "A" corresponds to 41 H (H denotes a hexadecimal notation and the same shall apply hereinafter). Then, font "A" as much as sixteen bytes is read out from the ROM and is displayed.
However, in the conventional pattern output apparatus using the foregoing method, as shown in FIG. 2 also, when the input code lies within a range of 00H to 1FH, a predetermined control is executed in accordance with the code or the like. There is no application to the control whereby some fonts are made coordinate with the codes in this range and these fonts are merely outputted. Therefore, in the foregoing ASCII codes, thirty-two kinds of codes among the 128 kinds of codes cannot be used to output the patterns, so that the remaining ninety-six kinds of codes are made coordinate with the fonts. Thus, the number of kinds of output characters is limited and this method itself is insufficient for the application to output a number of kinds of fonts.